The overall aim of the proposed research is to address theoretical questions about how people perceive, comprehend, and remember words and pictures. The research focuses on the early stages of processing in conditions of overload--when stimuli appear in a rapid sequence or when two targets are in close temporal proximity or both. Overload conditions can tell us how people allocate their attention and how they consolidate memory of a stimulus. In the experiments two words or pictures are presented close in time and therefore compete for limited processing resources. Potter, Staub, & O'Connor (2002) reported a surprising shift in attention between two words presented at stimulus onset asynchronies (SOAs) varying between 13 and 213 ms (the words appeared in adjacent streams of stimuli). At very short SOAs the second word was more likely to be reported, whereas at an SOA of 213 ms the reverse was the case, and the second word was often missed (an attentional blink). A two-stage competition theory is proposed: In Stage 1 detection of a possible target draws attentional resources, but attention is labile. If a second potential target is detected very soon after the first the two targets compete for resources. When one of the targets is identified as a particular word that word enters Stage 2 for consolidation in short-term memory. Stage 2 is serial: while one target is being processed, the other must wait in Stage 1 and may be forgotten. The 15 proposed experiments will test specific predictions of this model and will extend it to new domains. A computational version of this model will be developed. The long-term goal of the proposed research is to extend conclusions from this work to perception of the environment in normal viewing conditions, in order to answer important practical as well as theoretical questions about visual attention. [unreadable] [unreadable]